A few notes on usability.

When mouse is over the context menu for thumbnail, thumbnail loses focus. It should stay focused. Also the Properties option should be last on the menu with a divider (where preferences is at the moment)

The order of the little buttons at the top of the thumbnail needs changing to the order of usage. Suggest this order: Remove, Properties, Refresh. Oddly the mouse cursor changes from a hand to the default pointer when mousing over the icons, not sure what to suggest there but the context change is wrong. Also optional tooltips might be in order.

Lastly, not sure if Refresh All is supposed to try and refresh every single thumbnail regardless of if it's on the page or not. Suggest Refresh Page option as I just end up with 2 or 3 refreshed and all other thumbnails marked to refresh timing out. (Haven´t looked at how the new refresh interval feature affects this yet)

f 3.0.1 fd 2.8